Instructions

In a large bowl, mix the flour, 1/2 cup sugar, baking powder, cinnamon and salt. Cut in the butter until the mixture resembles coarse crumbs. Stir in the boiling water and mix until evenly moist.

In a saucepan, dissolve the cornstarch in cold water. Mix in the remaining 1 cup sugar, lemon juice and blackberries. Bring to a boil over medium to medium-high heat, stirring frequently until thoroughly mixed and all cornstarch has been completely dissolved. Pour mixture into an oven-safe baking dish.